The invention relates to molecular biology and microbiology, and more particularly, to fungi retrotransposons.
Retroelements are classified into different types as well as telomeres, group II introns, retrons, retroviruses, LTR retrotransposons, non-LTR retrotransposons and so on (Flavell, 1995). So far there are approximately 30 elements corresponding to LTR retrotransposons and non-LTR retrotransposons recognized in fungi (Daboussi and Capy, 2003). Some characterizations of LTR retrotransposons have gag gene encoded intracellular ribonucleoprotein particles (Shiba and Saigo, 1983), pr gene encoded protease, int gene encoded integrase, rt gene encoded reverse transcriptase and RNaseH such as Pyret (Nakayashiki et al., 2001) and MAGGY (Farman et al., 1996) from Magnaporthe grisea, REAL from Alternaria alternate (Kaneko et al., 2000) and Nht2 from Nectria haematococca (Shiflett et al., 2002). Some retroviruses contain env gene encoded envelope glycoprotein for virus particles entering a new cell besides using the same genes of LTR retrotransposons to achieve the same approach (Bénit et al., 2001). Then, non-LTR retrotransposons, also known as LINEs, have a significant feature of lacking long terminal repeats far from LTR retrotransposon such as Zorro from Candida albicans (Goodwin et al., 2001), Ylli from Yarrowia lipolytica (Casaregola et al., 2002) and marY2N from Tricholoma matsutake (Murata et al., 2001). Most of non-LTR retrotransposons have two open reading frames found in fungi. The first open reading frame is considered to be the gag gene containing cysteine-rich DNA binding domains, although the first open reading frame does not show a conserved protein sequence. The second open reading frame encodes several conserved domains including endonuclease, reverse transcriptase, RNaseH domains and zinc finger motifs. Phylogenetic comparisons of the protein sequences suggest that non-LTR retrotransposons are the ancestors of LTR retrotransposon (Malik et al., 1999). Moreover, the oldest non-LTR retrotransposons is encoded by a single open reading frame due to their simpler construction.
Non-LTR retrotransposons were recently classified into 11 clades described by Malik et al. (1999). The position of a new non-LTR retrotransposon can be clearly revealed by phylogenetic tree analysis. The phylogenetic tree construction is based on the strong conserved domain of reverse transcriptase. The endonuclease domain is not very strongly conserved, although it is also used to classify non-LTR retrotransposons. Furthermore, the evolution of non-LTR retrotransposon is usually based on vertical transmission (Malik et al., 1999), but Bov-B LINE is an exception by horizontal transfer (Kordi{hacek over (s)} and Guben{hacek over (s)}ek, 1998) since it is distributed in Squamata as well as in Ruminantia (Kordi{hacek over (s)} and Guben{hacek over (s)}ek 1999).
Monascus has been applied in the food industry for thousands of years in China. Recently, it has been found that Monascus produces several bioactive substances. These bioactive substances are mainly the secondary metabolites of Monascus, including substances for reducing hypertension, substances for anti-putrefaction of bacteria such as monascidin, anti-cancer substances, substances for lowering blood sugar, ergosteral, anti-oxidants, and inhibitors of cholesterol such as monacolin (Endo et al., 1986; Komagata et al., 1989). Therefore, Monascus has been valued as a functional health food in recent years. To date, only a little genetic information of Monascus is discovered, therefore, a need for the study of Monascus genetics is desirable.